Automatic transfer apparatus

ABSTRACT

Automatic device for delivering a calibrated quantity of a liquid from a first receptacle into a second receptacle by positioning a duct into the liquid to be delivered, aspirating the liquid into the duct for delivery into the second receptacle including control means cooperating with detectors of the position of the duct in the liquid and the aspirating duct.

United States Patent Inventor Robert Laueournet LHay-LesrRoses, FranceAppl. No. 793,498 Filed Jan 23, 1969 Patented Aug. 3, 1971 Assignee F.Hoffman-La Roche 8: Co.

Aktiengesellsdtaft, Switzerland Priority Jan. 24, 1968 France 137,316

AUTOMATIC TRANSFER APPARATUS 10 Claims, 3 Drawing Figs.

US. Cl 137/209, 74/89.2, 137/392, 137/395, 137/577, 222/400.7, 222/21,250/218 Int. I 867d 5/54 Field oiSearch 250/218;

AcruA r02 [56] References Cited UNITED STATES PATENTS 3,235,922 2/1966Kaji 222/70 X 3,367,195 2/1968 Racine 74/89.2 3,388,258 6/1968 Grant250/218 3,418,061 12/1968 Schultz 356/246 3,438,071 4/1969 Clark 137/392X 3,459,333 8/1969 lngelfield 222/373 X Primary Examiner-James W.Lawrence Assistant Examiner-C. M. Leedom Almmey--Sughrue, Rothwell,Mion, Zinn & Macpeak ABSTRACT: Automatic device for delivering acalibrated quantity of a liquid from a first receptacle into a secondreceptacle by positioning a duct into the liquid to be delivered,aspirating the liquid into the duct for delivery into the secondreceptacle including control means cooperating with detectors of theposition of the duct in the liquid and the aspirating duct.

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sum 2 OF 2 AUTOMATIC TRANSFER APPARATUS BACKGROUND OF THE INVENTION 1.Field of the Invention The present invention relates to an apparatus forthe automatic transfer of a given quantity of liquid from a containerwherein it is stored to another container and, more particularly, to theanalysis of a calibrated quantity of the liquid.

2. Description of the Prior Art Analyses having a high rate of liquidsamples are made by means of automatic analyzing apparatus. The samplesgenerally constitute either the liquid itself or a mixture in specificproportions of the liquid and reagents which are appropriate to theanalyses to be carried out.

Thus, many samples have particles in suspension which must not betransferred into an analysis tank, particularly blood samples.

SUMMARY OF THE INVENTION The present invention provides an apparatus forthe automatic transfer of a calibrated quantity of samples, for exampleblood samples for automatic analysis, while avoiding the contaminationof a liquid sample with another and external pollution. The presentinvention also provides an apparatus for the rapid transfer of acalibrated quantity of samples without taking particles in suspensionfrom a phase known as the sedimented phase of the said sample.

The automatic transfer apparatus has a quantity of liquid samplecontained in a first container for transfer to a second container. Afirst tube has ends adapted to be immersed respectively in the sampleand directed to the second container. A second tube is connected to asource of gas under pressure with the free end adapted to penetrate intothe said first container. Means for detecting the passage of the liquidsample are provided at a given point of the first tube. The ends of thefirst and second tubes which penetrate into the first container arefixed to the same support which itself is mobile is translationalmovement relative to the level of the liquid sample in the firstcontainer. The said support is driven in translational movement by bothan element for detecting contact between a point of the end of thesecond tube and the level of the liquid sample, and by the means fordetecting the passage of the sample in the second tube.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of apreferred embodiment of the apparatus according to the invention.

FIG. 2 is a perspective view of the driving element of the apparatusshown in FIG. 1.

FIG. 3 is a diagram illustrating the control sequences in time of theelement shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. I there is illustrated afirst container in which is stored a sample which is to be transferredto a second container for the purpose of analysis. The first container 1is q bottle carrying in ascending order a sedimented sample phase 4, aliquid sample phase 3 to be analyzed and a portion 2 from which air hasbeen partly evacuated. This bottle is hermetically closed by twoindividual plugs 14 and sealing the enclosure. These plugs are made of amaterial which can be readily perforated by hollow needles or the like,and advantageously retractable. The bottle is positioned below aneetile-carrying element 5 to which two needles 6 and 7 are fixed.

The first ends of the needles 6 and 7 are intended to pierce the plugs14 and I5 and for this purpose are cut in bevelled form. Advantageously,the portions of the two needles 6 and 7 which are intended to bepositioned in the bottle 1 are of unequal length, the correspondingportion of the needle 6 being longer than the corresponding portion ofthe needle 7 by several millimeters, for example 2 to 3 millimeters.

The needle-carrying element 5 also supports an arm 8 comprising at itsend, appropriately positioned, a photoelectric cell 9 excitedrespectively by light sources 22 arranged vertically at the other sidealong the bottle and represented diagrammatically. The cell 9 isconnected to a photoelectric detector 10. The needle 6 is elbowed insuch a manner that its second end is positioned in the second containeror bottle forming chamber 18.

Situated in the circuit of the needle 6 between the bottle 1 and thechamber 18, at a distance corresponding to the calibrated volume to betransferred, is a detecting gauge 11, in this case advantageously aconductivity-measuring gauge. This gauge is connected to a conductivitydetector 12. This gauge may also be of the photoelectic type. The secondend of the needle 7 is connected to a source of air or gas underpressure 19.

Between the two needles 6 and 7 is a device 13 similar to the detector12, which supplies a signal, the value of which is in accordance withthe electrical resistance between the two needles 6 and 7. The detectorcircuits l2 and 13 are connected electrically to a control unit 16 ofactuator 17. The actuator l7 imparts a rectilinear sequential movementto the needle carrier 5.

Before the electrical control signal appears at the control unit 16, theactuator 17 and the needle carrier 5 are in the upper position, theneedles are also in the upper position and a bottle 1 is positionedmechanically below the needle carrier 5.

When the control signal occurs, the actuator pushes the needles throughthe plugs 14 and 15 into the position illustrated in FIG. 1. The needle6 enters the limpid liquid and a fraction of a second afterwards theneedle 7, in its turn, contacts the liquid. The electrical resistancebetween the needles 6 and 7 which is considerable initially owing to thefact that all the parts in contact with the needles are of an insulatingcharacter has its resistance lowered and the detector circuit 13 trips,which sends an electrical signal into the control unit 16, whichsupplies a signal to the actuator to stop its downward travel. Theneedles 6 and 7 stop with the needle 6 below the surface level of theliquid and the needle 7 just in contact with the surface. The bevel ofthe needle 7 permits compressed air to enter the free portion 2 of thebottle without disturbing the surface of the liquid. The pressureestablished in the free portion pushes the liquid 3 in the needle 6 intothe duct. When the liquid under pressure reaches the detecting gauge 11,the conductivity-measuring detector 12 trips and sends a signal to thecontrol unit which operates the actuator in the reverse sense. Theneedles move upwards again until the needle 6 is above the surface ofthe liquid 3. At this instant electrical resistance between the twoneedles again becomes considerable. The circuit 13 again trips and bymeans of the control unit 16 again stops the upward travel of theactuator. The compressed air within the free space 2 pushes the liquidwhich has penetrated into the needle 6 towards its other end intocontainer 18. A zeroizing signal represented diagrammatically by theconnection 20 is applied to the control unit 16 and operates theactuator upwards, until the needles are situated outside the bottle 1.Another sequence can recommence in the form of a new signal applied tothe control unit 16, represented diagrammatically by the connection 21.

In cases where the surface level of the liquid 3 is too low, that is tosay the height of the liquid phase 3 is very slight, there is a riskthat the needle 6 may inspire sediment 4. For this purpose, the lightray emitted horizontally by the light source 22 does not pass throughthe sedimented phase 4 to cell 9 and cell 9 is not excited before thestopping sequence of the actuator 17 is completed. Consequently, theoperation of the actuator 17 is effected by the cell 9 by way of thedetecting element 10 which orders the actuator to move into the upperposition again. There is no longer a sample available for analysis, andthis can be indicated to the operator by means of a light indicator, forexample.

The actuator may comprise either a pneumatic jack operated byrapid-action electromagnetic valves, an electrohydraulic jack, or astep-by-step motor controlling a rack supporting the needle carrier 5 bymeans of a reduction gear, or any device for transmitting the aforesaidsequential movements. The gear-rack system may advantageously bereplaced by a known system of metal blades associated with a system ofcylindrical drums, transforming a circular movement into an alternatingrectilinear movement.

FIG. 2 shows one such embodiment.

In FIG. 2, a motor 23 which may be of a step-by-step type, drives a drum25. On this drum there are fixed one end of each flexible blade 26 and27. The other end of each blade is fixed to a plate 24 which drives theneedle carrier 5 and imparts the sequential movements to it.

The aforesaid sequential movements are indicated diagrammatically inFIG. 3 in which the positions of the actuator 17 representing thesuccession of sequences S are plotted as ordinates and the times t asabscissae.

At the beginning of the sequence, the actuator is in the upper positionindicated at the ordinate position P At time A, the arrival of thecontrol signal 21 triggers the sequence and the actuator descends. Attime B the actuator is at position P,, the needle 6 is immersed in theliquid phase 3 of the sample in the bottle 1 and the end of the needle 7touches the surface of the liquid phase; the liquid can be deliveredinto the needle 6; the time interval AB corresponds to the descent ofthe needles into the bottle 1.

At time C the value of the calibrated volume of the sample forced intothe tube is reached, the actuator which had been in the position P up tothis instant receives from the detector 12 a control signal to moveupwards again; the time BC is the calibrating time.

At time D the signal coming from the detector 13 is applied to theactuator which is positioned at P the ends of the needles 6 and 7 arestill in the bottle 1 but are no longer in contact with the liquid phase3 and the calibrated volume of the liquid inspired may be transferredinto the chamber 18. The time CD is the time corresponding to that inmoving the needles upwards again out of the liquid. At time E thecalibrated volume of liquid is entirely transferred into the chamber 18,and the actuator can again be returned to the upper position P,,. Attime F the control signal for zeroizing 20 is applied and the actuatoris maintained in the upper position i until a new identical sequenceoccurs.

It appears, in the succession of sequences S, that the precision of thecalibration may be affected by the time CD. Thus it is possible in orderto have a good standard of precision either to act on the gas underpressure, the detector 12 stopping the supply of gas under pressure, orto take the time CD into account in calibration if this is chosen to beconstant. The present invention affords many advantages. Moreparticularly, the bottles such as the bottle 1 may constitute acontinuous linear chain and be positioned automatically below the needlecarrier 5. Likewise the chambers, such as the chamber 2, closed orotherwise, may be chambers comprised by a supporting film. This film maybe driven in a step-by-step movement so that the chambers comesuccessively to the position under the corresponding end of the needle6, this end being also cut in bevelled form so as to pierce through theupper portion of the closed chamber.

The transfer device as described constitutes, therefore, an automaticpipette for transfer of liquid substances which can be provided for acontinuous automatic sample-analyzing line.

Furthermore, if external pollution of the samples has been avoided bythe fact that transfer is effected from a bottle to a hermeticallyclosed chamber, contamination of one sample with another is alsoavoided. in fact, the transfer of samples is effected rapidly andsuccessively by means of the needle 6, the samples are forced in at oneend and ejected at the other end, and the liquid passes through theneedle, which has a smooth internal surface, by being pushed by a strongblast of air and entirely discharged. The apparatus also permitstransfer only of the liquid part of the samples with analysis effectedsolely on a calibrated volume of this liquid part.

What i claim is: 1. Automatic apparatus for the transfer of apredetermined quantity of a liquid sample contained in a first containerto a second container, comprising: a first tube one end portion of whichis adapted to be immersed in said sample and the other end portionpenetrating said second container, a second tube connected to a sourceof gas under pressure with its free end portion adapted to penetratesaid first container, said one end portion of said first tube beinglonger than said free end portion of said second tube, first means fordetecting the passage of said liquid sample at a given point of saidfirst tube, a common support for fixedly carrying the end portions ofsaid first and second tubes which penetrate said first container, meansfor translationally moving said support relative to the surface level ofsaid liquid sample in said first container, and means for controllingsaid translational movement by said first detecting means.

2. The apparatus as claimed in claim 1 further comprising second meansfor detecting contact between the free end portion of the second tubeand the surface level of said liquid sample, and means for furthercontrolling translational movement of said support by said seconddetecting means.

3. The apparatus as claimed in claim 2 wherein said first and secondtube portions penetrating said first container are of unequal lengthsuch that the one end of said first tube is situated below the surfacelevel of the liquid sample when the free end of said second tube issubstantially flush with said surface,

4. The apparatus as claimed in claim 3 wherein the ends of said firstand second tubes which penetrate said first container are bevelled.

5. The apparatus as claimed in claim 2 wherein said second detectingmeans comprises a conductivity-measuring device electrically connectedbetween said first and second tubes.

6. The apparatus as claimed in claim 2 wherein said liquid sample insaid first container has a sedimented phase, and further comprisingmeans for preventing translational movement of said support below adefined lower level corresponding to the passage of the one end of thefirst tube into the sedimented phase of said sample, thereby to preventthe transfer of sediment from said first container to said secondcontainer.

7. The apparatus as claimed in claim 6 wherein said preventing meanscomprises a photoelectric detector and a light source arrangedrespectively on opposed sides of said first container, with saidphotoelectric detector being unenergized by the light source when it isadjacent the sedimented phase of the liquid sample to prevent furtherdownward movement of said tubes with respect to said first container.

8. The apparatus as claimed in claim 7 wherein said photoelectricdetector is fixed to said support for translational movement therewith.

9. The apparatus as claimed in claim 8 wherein said translationalmovement means for said support comprises an actuator operativelycoupled thereto.

10. The apparatus as claimed in claim 9 wherein said actuator comprisesa driven drum and at least two metal blades each having first ends fixedto the periphery of said drum and wrapped in opposite directions, andsecond ends fixed to said support for transforming circular movementinto rectilinear movement.

1. Automatic apparatus for the transfer of a predetermined quantity of aliquid sample contained in a first container to a second container,comprising: a first tube one end portion of which is adapted to beimmersed in said sample and the other end portion penetrating saidsecond container, a second tube connected to a source of gas underpressure with its free end portion adapted to penetrate said firstcontainer, said one end portion of said first tube being longer thansaid free end portion of said second tube, first means for detecting thepassage of said liquid sample at a given point of said first tube, acommon support for fixedly carrying the end portions of said first andsecond tubes which penetrate said first container, means fortranslationally moving said support relative to the surface level ofsaid liquid sample in said first container, and means for controllingsaid translational movement by said first detecting means.
 2. Theapparatus as claimed in claim 1 further comprising second means fordetecting contact between the free end portion of the second tube andthe surface level of said liquid sample, and means for furthercontrolling translational movement of said support by said seconddetecting means.
 3. The apparatus as claimed in claim 2 wherein saidfirst and second tube portions penetrating said first container are ofunequal length such that the one end of said first tube is situatedbelow the surface level of the liquid sample when the free end of saidsecond tube is substantially flush with said surface,
 4. The apparatusas claimed in claim 3 wherein the ends of said first and second tubeswhich penetrate said first container are bevelled.
 5. The apparatus asclaimed in claim 2 wherein said second detecting means comprises aconductivity-measuring device electrically connected between said firstand second tubes.
 6. The apparatus as claimed in claim 2 wherein saidliquid sample in said first container has a sedimented phase, andfurther comprising means for preventing translational movement of saidsupport below a defined lower level corresponding to the passage of theone end of the first tube into the sedimented phase of said sample,thereby to prevent the transfer of sediment from said first container tosaid second container.
 7. The apparatus as claimed in claim 6 whereinsaid preventing means comprises a photoelectric detector and a lightsource arranged respectively on opposed sides of said first container,with said photoelectric detector being unenergized by the light sourcewhen it is adjacent the sedimented phase of the liquid sample to preventfurther downward movement of said tubes with respect to said firstcontainer.
 8. The apparatus as claimed in claim 7 wherein saidphotoelectric detector is fixed to said support for translationalmovement therewith.
 9. The apparatus as claimed in claim 8 wherein saidtranslational movement means for said support comprises an actuatoroperatively coupled thereto.
 10. The apparatus as claimed in claim 9wherein said actuator comprises a driven drum and at least two metalblades each having first ends fixed to the periphery of said drum andwrapped in opposite directions, and second ends fixed to said supportfor transforming circular movement into rectilinear movement.